That's weird. I have no idea what could be the problem, other than it is probably the converter. My only suggestion would be to try another battery anyway, just to prove that's not the problem. I'm not suggesting you buy a new one, just take it out of something else temporarily.
For those of you who are TT smart and FW dumb, landing gear is the term used to refer to the front two jacks that lift the front of the trailer. They basically are the FW version of a tongue jack, except they're power (on the newer ones) and there's two of them.
2007 T-286SR Cherry/Granola, #6236, original owner, current mileage: 9467.8 (as of 5/26/19)
1997 T-2653 Blue Denim, #5471
1979 12 1/2' MC, Beige & Avocado, #4639
Past Sunlines: '97 T-2653 #5089, '94 T-2251, '86 T-1550, '94 T-2363, '98 T-270SR